A kind of hierarchical porous char (SC CA/Zn ) was prepared from sewage sludge by a new two-step pore-fabricating process coupling citric acid (CA) with ZnCl 2 in a pyrolysis process. The char was characterized by element analysis, N 2 -adsorption and mercury intrusion measurement etc. It is found that coupling CA and ZnCl 2 can synergistically fabricate pores in the pyrolysis process, resulting in a hierarchical porous char, SC CA/Zn , with the largest S BET of 867.6m 2 g −1 due to the fact that the former contributes to the fabrication of macro-pores, which provides more space for fabricating meso- and micro-pores by ZnCl 2 activation. Although the S BET of SC CA/Zn was 15% less than that of activated carbon fiber (ACF, S BET =999.5m 2 g −1 ), SC CA/Zn had a higher toluene adsorption capacity (0.83gg −1 ) than ACF. The inconsistence between their S BET and adsorption capacity can be ascribed to the strong hydrophobic property of SC CA/Zn .